Shock absorbers for use by workers in a fall protection systems are, in general, old and well known. Some examples of such prior systems are shown in U.S. Pat. Nos. 3,762,507, 2,724,463 and 2,796,953. Other shock absorbing devices for use in straps have been shown in devices for use with motor vehicle seat belts and with parachute harnesses. Such examples are shown in U.S. Pat. Nos. 3,277,855, 4,027,905, 3,973,650, 3,897,106, 3,550,957, 3,547,387 and 2,474,124. Several of these prior art devices, including the last mentioned above, utilize breakable stitching holding together more than one layer of webbing to absorb shock. None of these devices, however, utilizes the mechanism of the instant invention, which will be more fully described hereinafter.